Ice breaker (variants), method and system for single-support mooring and servicing ships

ABSTRACT

To ensure the possibility of offshore shipping of a liquid medium, primarily oil, from an onshore tank farm into sea-going tankers in the winter time in the ice conditions by ensuring both mooring to an offshore terminal and single-point mooring of a tanker at any time, without depending on the dominating wind and sea condition, in a direction most convenient for it with the possibility of its roundabout turning, with the subsequent servicing of it by transporting a liquid medium into such a tanker the following transformations have been made: 
         a known ice breaker ( 1 ) is provided with: a diving station ( 5 ) installed on its deck ( 3 ), the said diving station being provided with a diving trunk ( 6 ) made in the hull ( 2 ) of the ice-breaker ( 1 ), a device for the protection of a flexible hose ( 8 ) of an underwater pipeline against ice action, the said device being made, according to the first embodiment, in the form of a cylinder ( 7 ) provided with guides ( 13 ) for moving in a guiding trunk ( 10 ) made in the stern side of the hull ( 2 ). According to the second embodiment the ice-breaker ( 1 ) is provided with a device for the protection of the flexible hose ( 8 ) of the underwater pipeline against ice action, the said device being made in the form of a pontoon ( 15 ) provided with a trunk ( 16 ) for servicing the flexible hose ( 8 ) and installed in the travel position on the deck ( 4 );    a system of single-point mooring and servicing of ships is provided with the ice-breaker ( 1 ), which is claimed as an invention, for ensuring offshore shipping of oil, a mooring line and a hose for transporting a liquid medium are made as a single hose-mooring line ( 28 ); a method of single-point mooring and servicing of ships, primarily tankers ( 9 ) is carried out with the use of the claimed ice-breaker ( 1 ) and the hose-mooring line ( 28 ).

This invention relates to ship-building and may be used inpost-equipping ice-breakers for the purpose of offshore loading of aliquid medium, primarily oil, into tankers in the winter time in the iceconditions.

The invention also relates to methods and devices for single-pointmooring of ships, primarily tankers, and the possibility of loading themwith a liquid medium, primarily oil, in the winter time in the iceconditions with the use of the claimed ice-breaker.

At present, due to an increase in oil consumption, its production atoff-shore fields both abroad and in the Russian Federation (the KaraSea, the Barents Sea) has becoming more intensive. Thus, in the RussianFederation, in the Timano-Pechora Province rich oil fields have beendiscovered. Severe climatic conditions are typical for this province:the cold winter period with negative temperatures and ice formation onthe sea lasts from November till May. Such climatic conditions putforward new requirements to systems for transferring oil from land intoa tanker, which should be able to ship oil not only in the short warmperiod, but also during the long cold period of time.

Known in the art is a ship for ice navigation, comprising a hull withthe double bottom and double sides, an ice-breaking stem, sternpropellers, a propulsion and steering complex of water-jet type havingside water passages in communication with the outboard water area, thesaid complex being installed in the ship forebody and arranged in anelongated extension (see USSR Inventor's Certificate No. 1309473 for theinvention “A ship for ice navigation”. IPC B63B 35/08. Application No.3964759/27-11, priority date as of Sep. 17, 1985. Published on Oct. 23,1988, Off. Bull. No. 39. Inventors—A. V. Pilipenko, Ye. M. Novoseltsev),[1].

In order to load floating objects with heavy cargoes, sluice valves areopened and outboard water freely comes into the hold until the time whenits level reaches the existing waterline. The floating objects are movedto the hold, the gate is closed and the water is pumped out of the hold.

The said ship enables to lead cargoes, namely floating objects with bulkcargoes. The ship is very complex and non-fit for shipping a liquidmedium.

On the basis of an analysis of information on the state of the art inthis field, the closest, from among the known ice-breakers, is theice-breaker comprising the hull having vertical through guiding trunksand the deck (see USSR Inventor's Certificate No. 1106730 for theinvention “An ice-breaker”. IPC B63B 35/08, priority date as of Apr. 7,1982, Application No. 3419886/27-11, published on Aug. 7, 1984, Off.Bull. No. 29—a prototype) [2].

The said ice-breaker performs only its main functions—breaking the icecover for making the way (passage) for other ships and providing themwith necessary assistance when moving in ice, as well as navigatesindependently.

The vertical through guiding trunks, as made in the hull of the knownice-breaker, are intended for guiding devices additionally breaking theice cover.

Thus, the analysis of the found information on the state of the art hasshown that the existing ice-breakers perform, principally, their mainfunctions—breaking of the ice cover and piloting ships in the iceconditions.

Known in the art is a method of mooring and servicing ships, accordingto which an annular mooring recess, as made in the lower part of theship's hull, a mooring member coupled by its upper part with the saidrecess and connected by a plurality of ropes holding the said member ata pre-determined depth, a device for lifting the mooring member, adevice for quickly admitting water into the ship's hull through inputholes, as located inside the said recess, are used (see RF Patent No.2146633 for the invention “A ship mooring system”. IPC B63B 22/02,Application No. 95113430/28 with the priority date as of Dec. 29, 1993.Published on Mar. 20, 2000. Applicant—Jens Korsgord (DK) [3].

The said method of mooring is rather complex; it does not ensuresufficient maneuverability of a moored ship. The requirements to theoffshore work safety when mooring and loading oil are not complied with.Furthermore, the said method is absolutely not applicable in the iceconditions.

An analysis of the information selected during a search in this fieldhas enabled to identify the closest method of single-point mooring ofships, preferably tankers, according to which for transporting a liquidmedium into a moored tanker or out of it a fixed construction secured tothe sea bed, the mooring chain of a tanker and at least one flexiblepipeline are used; forward and rotational movements of a tanker arecompensated by turns of interconnected members, one of which issupported by the said fixed construction secured to the sea bed, and themooring chain of a tanker and a flexible pipeline for transporting aliquid medium into a tanker or out of it are connected to another member(see RF Patent No. 2133687 for the invention “A method of single-pointmooring of ships and a system for carrying out same (embodiments). IPCB63B 22/02. Application No. 97104654/18 with the priority date as ofMar. 20, 1997. Published on Jul. 27, 1999. Applicant—Tecnomare S. p. A.(Italy)—a prototype) [4].

The said method is suitable for offshore single-point mooring of a ship,ensures positioning, at any time depending on the dominating wind andsea condition, of a moored tanker in a direction most convenient for itwith the possibility of its roundabout turning and positioning by itsbow downwind. But the said method is not sufficiently secure due to thepossible twisting of the mooring chain and the flexible pipeline, whichgo in parallel, in the process of a tanker's turns.

Known in the art is a system of mooring ships, comprising an annularmooring recess, as made in the lower part of the ship's hull, a mooringmember coupled by its upper part with the said recess and connected by aplurality of ropes holding the said member at a pre-determined depth, adevice for lifting the mooring member, a device for quickly admittingwater into the ship's hull through input holes, as located inside thesaid recess, see [3].

The said system of mooring is rather complex, does not ensure sufficientmaneuverability of a moored ship, does not ensures safety of mooring andoil shipping operations, is not suitable for using in the iceconditions.

On the basis of an analysis of the information on the state of the artin this field, from among the known systems the closest is the system ofsingle-point mooring of ships, preferably tankers, comprising a fixedconstruction secured to the sea bed, the mooring chain of a tanker andat least one flexible pipeline; a toroidal device connected to the saidfixed construction, a yoke, the tips of the bifurcated part of which areconnected to the said toroidal device with the possibility of turningthe said yoke around the horizontal axis (turning axis) and the secondend of the yoke is connected to the mooring chain of a tanker—aprototype, see [4].

The said system is suitable for offshore single-point mooring of a ship,ensures positioning, at any time depending on the dominating wind andsea condition, of a moored tanker in a direction most convenient for itwith the possibility of its roundabout turning and positioning by itsbow downwind. But the said system is not suitable for mooring andservicing tankers in the ice conditions. Furthermore, the system isinsufficiently secure due to the possible twisting of the mooring chainand the flexible pipeline in the process of the tanker's turns.

Thus, the analysis of the found information on the state of the art hasshown that the existing methods and systems of single-point mooring andservicing of takers do not enable to perform mooring and transportingoil into a tanker in the winter time in the ice conditions.

The claimed group of inventions (“An ice-breaker (embodiments), a methodand a system of single-point mooring and servicing of ships”) enables toobtain a new technical result—the possibility of offshore shipping of aliquid medium, primarily oil, from an onshore tank farm into sea-goingtankers in the winter time in the ice conditions by ensuring bothmooring to an offshore terminal and single-point mooring of a tanker atany time, without depending on the dominating wind and sea condition, ina direction most convenient for it with the possibility of itsroundabout turning, with the subsequent servicing of it by transportinga liquid medium into such a tanker.

The below-stated totality of essential features characterizes theessence of the claimed group of inventions and helps to achieve a newtechnical result.

First Embodiment of the Ice-Breaker

An ice-breaker, primarily for carrying out offshore transportation of aliquid medium, preferably oil, comprising the hull with vertical throughguiding trunks and the deck, characterized in that it is equipped with adiving station installed on the deck and communicating with one of thesaid vertical through trunks, which is intended for lowering and raisinga diver, a device for the protection of a flexible hose of an underwaterpipeline against ice action, which is made in the form of a cylinderprovided with guides for moving in another vertical trunk made in thestem side of the hull and installed in its travel position on theafterdeck.

A technical result is also achieved due to the fact that the saidice-breaker is equipped with cargo lowering and lifting mechanisms and atowing device.

A technical result is also achieved due to the fact that the ice-breakeris equipped with a container, which is installed on the deck andcontains oil gathering equipment and fire-fighting means.

A technical result is also achieved due to the fact that the ice-breakeris equipped with a removable platform, which is installed on theafterdeck and has a container for gathering oil spills and an ecologicalmonitoring laboratory.

Second Embodiment of the Ice-Breaker

An ice-breaker, primarily for carrying out offshore transportation of aliquid medium, preferably oil, comprising the hull with a verticalthrough guiding trunk and the deck, characterized in that it is equippedwith a diving station installed on the deck and communicating with thesaid vertical through trunk, which is intended for lowering and raisinga diver, a device for the protection of a flexible hose of an underwaterpipeline against ice influence, which is made in the form of a pontoonhaving a trunk for servicing of the flexible hose and installed in itstravel position on the deck.

A technical result is also achieved due to the fact that the saidice-breaker is equipped with cargo lowering and lifting mechanisms and atowing device.

A technical result is also achieved due to the fact that the ice-breakeris equipped with a container, which is installed on the deck andcontains oil gathering equipment and fire-fighting means.

A technical result is also achieved due to the fact that the ice-breakeris equipped with a removable platform, which is installed on theafterdeck and has a container for gathering oil spills and an ecologicalmonitoring laboratory.

A method of single-point mooring of ships, primarily tankers in the iceconditions, according to which a fixed construction secured to the seabed is used, the said construction being provided with a device beingconnected to it with the possibility of turning around the vertical axisand a valve for a liquid medium, primarily oil, a mooring line and aflexible pipeline for transporting a liquid medium into a moored tankerthrough the cargo-receiving device of the tanker, characterized in thatfor mooring a tanker and transporting a liquid medium a mooring line anda hose, which are made as a single hose-mooring line which bitter end issecured on the fixed construction device, are used, an ice-breakerensuring offshore shipping of oil is additionally used, which has adiving station installed on the deck and communicating with a trunk forlowering and raising a diver, who opens the valve for a liquid medium,finds the hose-mooring line and raises it to the tanker after emergencydetachment of it from the cargo-receiving device of the tanker in theconditions of close and drifting ice.

The achievement of a technical result is also supported by that a weightis attached to and a damper, which is made, preferably, in the form of acable and connected on one its end with the device of the fixedconstruction and on the other end with the said weight, is installed ona section of the hose-mooring line near its bitter end.

The technical result is achieved also due to the fact that the sectionof the hose-mooring line, which is located between the device of thefixed construction and the weight, is installed outside the area ofaction of power loads.

A system of single-point mooring of ships, primarily tankers in the iceconditions, comprising a fixed construction secured to the sea bed andhaving a device being connected to it with the possibility of turningaround the vertical axis and a valve for a liquid medium, primarily oil,a mooring line and a flexible pipeline for transporting a liquid mediuminto a moored tanker through the cargo-receiving device of the tanker,characterized in that the mooring line and the hose for transporting aliquid medium are made as a single hose-mooring line which bitter end issecured on the fixed construction device; the system is provided with anice-breaker ensuring offshore shipping of oil, which has a divingstation installed on the deck and communicating with a trunk, arrangedin the hull, for lowering and raising a diver, who opens the valve for aliquid medium, finds and raises the hose-mooring line after emergencydetachment of it from the cargo-receiving device of the tanker in theconditions of close and drifting ice.

The achievement of a technical result is also supported by that thesystem is provided with a weight is attached to a section of thehose-mooring line near its bitter end and a damper, which is made,preferably, in the form of a cable and connected on one its end with thedevice of the fixed construction and on the other end with the saidweight.

The technical result is achieved also due to the fact that the sectionof the hose-mooring line, which is located between the device of thefixed construction and the weight, is outside the area of action ofpower loads.

So, the analysis of the found information on the state of the art in thesaid fields and the essence of the claimed group of inventions haveshown that the latter comply with the patentability criterion ofnovelty.

The provision of an ice-breaker comprising the hull with the verticalthrough guiding trunks made in it, and the deck, the diving stationinstalled on the deck and connected with one of the vertical throughtrunks, which is intended to ensure lowering and raising a diver,enables to lower and raise a diver from the deck for conducting thenecessary underwater works, namely: search on and raise of the flexiblehose of the underwater pipeline from the sea bed, the works required forthe preparation of the oil shipping system for the start-up.

The provision of an ice-breaker with a device for the protection of theflexible hose of the underwater pipeline against ice action, inparticular, according to the first embodiment of the ice-breaker, with adevice made in the form of a cylinder provided with guides for moving inthe vertical trunk made in the stem side of the hull and installed inits travel position on the afterdeck prevents the flexible hose frombeing damaged by floating ice and protects it against bends during itsraising from the sea bed onto the ice-breaker deck/lowering to the seabed from the ice-breaker deck and in the course of oil loading into atanker owing to movements of the flexible hose inside the cylinder. Itcontributes to the achievement of the stated technical result.

The provision of an ice-breaker, according to the 2nd embodiment, with adevice for the protection of the flexible hose of the underwaterpipeline against ice action, which is made in the form of a pontoonhaving a trunk for servicing the flexible hose installed in its travelposition on the deck of the ice-breaker, also ensures the protection ofthe latter against finely broken ice during operations of raising theflexible hose from the sea bed onto the ice-breaker deck/lowering theflexible hose to the sea bed from the ice-breaker deck and in the courseof oil loading into a tanker via the flexible hose in the winter time inthe conditions of initial ice formation.

The provision of the ice-breaker with cargo lowering and liftingmechanisms enables to lower the pontoon on the water, to raise theflexible hose of the underwater pipeline and to transfer it from theice-breaker to a tanker.

The provision of the ice-breaker with a towing device enables theice-breaker to perform an additional function—to tow means oftransportation, in particular a tanker, in a case of the latter'sfailure to move.

The provision of the ice-breaker with a container with oil gatheringequipment and fire-fighting means, as installed on the deck, enables theice-breaker to perform new functions in addition to the above indicatedones, namely: to localize emergency spills of oil and extinguish firespossible during loading oil into a tanker, which, in combination withthe other features, contributes to the achievement of the stated result.

The provision of the ice-breaker with a removable platform with acontainer for collecting oil spills, as installed in the afterdeck,enables to collect possible spills of oil during its transportation,thus preventing the ice-breaker deck from becoming dirty and,consequently, the environment from being polluted.

The provision of the ice-breaker with an ecological monitoringlaboratory also enables to perform the above-said function—preventingthe environment in the area of oil shipping from being polluted.

Consequently, the ice-breaker claimed as an invention not only ensuresthe fulfillment of its direct functions, i.e., breaking the ice cover,but also assists in performing new functions, namely: salvage works inaccident cases involving a tanker (failure to move, grounding, etc.),liquidation of emergency spills of oil, liquidation of fires, preventionof the environment in the area of oil transportation from being polluted(ecological monitoring).

Thus, the ice-breaker claimed as an invention, its new totality ofessential features both according to the 1st and the 2nd embodimentsenables to achieve a new technical result as well as to perform a numberof new functions not peculiar to an ice-breaker, but necessary forachieving a technical result.

The method of single-point mooring and servicing of ships, primarilytankers, according to which a fixed construction secured to the sea bedis used, the said construction being provided with a device beingconnected to it with the possibility of turning around the vertical axisand a valve for a liquid medium, primarily oil, a mooring line and aflexible pipeline for transporting a liquid medium into a moored tankerthrough the cargo-receiving device of the tanker, ensures single-pointmooring of tankers and their servicing for transporting a liquid mediumoffshore at any time, without depending on the dominating wind directionand sea condition, in a direction most convenient for it with thepossibility of its roundabout turning.

The making of the hose for transporting a liquid medium and the mooringline in the form of a single hose-mooring line attached by its bitterend to the device of the fixed construction enables the reliable andhigh quality single-point mooring and transportation of a liquid mediumdue to the lack of twisting of the hose and the mooring line andsimplified work of a diver with the single hose-mooring line, whichcontributes to the achievement of a technical result.

Also, the additional use in the method of an ice-breaker ensuringoffshore shipping of oil, which has a diving station installed on thedeck and communicating with a trunk, as arranged in the hull, forlowering and raise of a diver, enables not only to make the way for atanker in ice in the winter time to a place of mooring and servicing andcontinuously clean the latter from ice, but also to ensure lowering andraise of a diver through the ice-breaker trunk. A diver opens a valve,which is arranged on the fixed construction, for a liquid medium for thepurpose of transporting it into the tanker. Furthermore, a diverconducts a search and raise of the hose-mooring line detached from thecargo-receiving device of a tanker in emergency situations and in theconditions of close and drifting ice.

The system of single-point mooring of ships, primarily tankers,comprising a fixed construction secured to the sea bed and having adevice being connected to it with the possibility of turning around thevertical axis and a valve for a liquid medium, primarily oil, a mooringline and a flexible pipeline for transporting a liquid medium into amoored tanker through the cargo-receiving device of a tanker, ensuressingle-point mooring of tankers and their servicing for transporting aliquid medium offshore at any time, without depending on the dominatingwind in a direction most convenient for a tanker with the possibility ofits roundabout turning.

The making of the hose for transporting a liquid medium and the mooringline in the form of a single hose-mooring line attached by its bitterend to the device of the fixed construction prevents the hose and themooring line twisting, enables to moor a ship economically and reliablyand makes possible to load a liquid medium into a tanker.

The provision of the system with a weight secured to the hose-mooringline near its bitter end and with a damper preferably made in the formof a cable and connected on one its end with the device of the fixedconstruction and on the other end with the weight, and the arrangementof the area of the hose-mooring line, which is between the device of thefixed construction and the weight, outside the area of action of powerloads ensures not only the hose-mooring line being on the sea bed in thenon-operating condition, but also removal of a maximum power load fromthe area of the hose-mooring line and its transfer via the damper,preferably made in the form of a cable, and via the device of the fixedconstruction onto the latter. It contributes to reliable andhigh-quality single-point mooring of a ship and loading of a liquidmedium into the latter, which, in combination with the other features,contributes to the achievement of the technical result.

The provision of the system with an ice-breaker ensuring offshoreshipping of oil, which has a diving station installed on the deck andcommunicating with a trunk, as arranged in the hull, for lowering andraise of a diver, enables not only to make the way for a tanker in iceand continuously clean the a place of mooring and servicing from ice,but also to ensure lowering and raise of a diver through the ice-breakertrunk for the purpose of carrying out underwater technical works. First,a diver opens a valve for a liquid medium on the fixed constructionsecured to the sea bed. Second, if an emergency situation occurs duringtransporting oil into a tanker, the hose-mooring line automaticallydetaches from the cargo-receiving device of the tanker and falls ontothe sea bed. After liquidating the emergency situation it is necessaryto resume transporting oil into the tanker. For this, with the help of adiver lowered from the ice-breaker the hose-mooring line is found andraised to the tanker, Furthermore, in the conditions of close anddrifting ice, when the commonly used raise of the hose-mooring line isimpossible, a diver also ensures a search and raise of the hose-mooringline from the sea bed to the tanker.

Thus, the claimed totality of the essential distinctive features of boththe method and the system of single-point mooring of ships contributesto the achievement of a new technical result. Consequently, the claimednew totality of the essential features of both the ice-breaker(embodiments) and the method and the system of single-point mooring ofships enables to achieve the stated new technical result—the possibilityof offshore shipping of a liquid medium, primarily oil, from the onshoretank farm to sea-going tankers in the winter time in the ice conditionsby ensuring both mooring to an offshore terminal and single-pointmooring of a tanker at any time, without depending on the dominatingwind and sea condition, in a direction most convenient for it with thepossibility of its roundabout turning, with the subsequent servicing ofit by transporting a liquid medium into such a tanker.

In the course of an information search, which has been conducted by theapplicant in this technical field, only individual distinctive featuresof the claimed inventions have been found among the known facilities ofthe same purpose, namely:

-   -   1. A guiding trunk for servicing a cylinder (see RF Patent No.        2119874), it is identical to the claimed one as to the purpose        and the function.    -   2. A pontoon (see USSR Inventors' Certificates Nos. 1011499,        846498, 618308), but the purpose and the function of the pontoon        in these solutions are completely different from those in the        claimed invention.    -   3. A guiding cylinder with guiding members for moving inside a        trunk (see RF Application No. 95107661, IPC B63B 22/02, for the        invention “A device for directing a subsea loading/unloading        buoy into the receiving space in the ship's bottom”). But the        function is different from that in the claimed invention.    -   4. Protection devices (see USSR Inventor's Certificate No.        1751043—in the ship's hull a square hatch is made; USSR        Inventor's Certificate No. 1093611—a protective ring). But the        form, the purpose and the function of the known protective        devices are different from those in the claimed totality of the        essential distinctive features.    -   5. Known in the art are supplying ice-breakers, which are        equipped with a towing device and fire-fighting equipment for        working offshore (see magazines “Sudostroenie za rubezhom”,        1984, No. 5, p. 65; “Morskoy flot”, 1999, No. 2, p. 25;        “Sudostroenie”, 1990, No. 10, p. 3-5).    -   6. Also known in the art are vertical through guiding trunks        made in the hull of an ice-breaker (see USSR Inventor's        Certificate No. 1106730 for the invention “An ice-breaker”) But,        the purpose and the functions of the known trunks are different        from those in the claimed solution.

Moreover, no other distinctive features are identified in the state ofart; their form, arrangement, ties between members as well as mostidentified features have another purpose, function and form; also, thetotality of the essential distinctive features of the claimed group ofinventions has not been found in the course of the search conducted.Thus, on the basis of an analysis of the found information on the stateof the art in this field and an analysis of the totality of theessential distinctive features of the claimed group, which are united bythe single inventive concept of the inventions, the latter do notobviously follow from the state of the art. Consequently, the claimedgroup of inventions has the patentability criterion of inventive step.

The claimed group of inventions “An ice-breaker (embodiments), a methodand a system of single-point mooring and servicing of ships” is furtherexplained on the drawings, where:

FIG. 1 shows the ice-breaker for offshore shipping of a liquid medium,primarily oil, a side view.

FIG. 2—the same, a top view, a layout of the main deck.

FIG. 3—the same, a top view, a layout of the forecastle deck.

FIG. 4 shows the device for the protection of the flexible hose of theunderwater pipeline, which is made in the form of a cylindrical tubule.

FIG. 5 shows the use of the ice-breaker according to the 1st embodiment.

FIG. 6 shows the use of the ice-breaker according to the 2nd embodiment.

FIG. 7—the same as in FIG. 6, a embodiment of locating the ice breakerat a distance from a tanker.

FIG. 8 shows the system of single-point mooring in the initialcondition.

FIG. 9—the same, surfacing of remotely controlled buoys.

FIG. 10—the same, raising the hose-mooring line.

FIG. 11—the same, attaching the hose-mooring line to the cargo receivingdevice and transporting of a liquid medium.

FIG. 12—the same as in FIG. 8, when working in the conditions ofdrifting ice at the time of searching for the end of the hose-mooringline by a diver.

The ice-breaker 1 (see FIG. 1) for offshore shipping of oil comprisesthe hull 2 with the main deck 3 (see FIG. 2) and the forecastle deck 4(see FIG. 3). On the deck 3 the diving station 5 is arranged, which isequipped with the diving trunk 6 arranged in the hull 2 of theice-breaker 1 and intended for lowering and raising a diver.

On the afterdeck 3 the device (see FIGS. 1, 2, 4, 5) is arranged, whichis made in the form of the cylindrical tubule 7 and intended to protectthe flexible hose 8 of the underwater pipeline with the valve (notshown) against ice action during lowering/raising operations and in theprocess of oil transporting from the pipeline via the hose 8 into thetanker 9. In the hull 2 of the stem side of the ice-breaker 1 thevertical through guiding trunk 10 is arranged for servicing thecylindrical tubule 7. On the deck 3 of the ice-breaker 1, in its stemside the lowering/raising mechanism made is arranged, which is made inthe form of the capstan 11 (see FIG. 2) with the cable 12, the latterbeing able to pass through the truck 10 for servicing the tubule 7. Thelatter is provided with the guides 13 for making its movements in thetrunk 10 possible. In the travel position the tubule 7 is arranged andsecured in the afterdeck 3 of the ice-breaker 1 (see FIG. 4) and in theoperation position the tubule 7 is lowered through 10 so as its loweredge 14 is located below the base of floating ice at 0.5 m or 2 m lowerthan the constructive waterline (CWL) of the ice-breaker 1.

According to the second embodiment of the invention the ice-breaker 1 isequipped with the device for the protection of the flexible hose 8,which is made in the form of the pontoon 15 (see FIGS. 3, 6, 7) havingin its central portion the trunk 16 for servicing the hose 8, while thesaid pontoon is arranged in the travel position on the deck 4 of theice-breaker 1. The pontoon 15 is made, according to one of theembodiments, rectangular, in the form of a welded steel structure. Inorder to ensure the required draft (app. 2 m), the lower portion of thepontoon 15 is made permeable for filling it with air or water throughthe corresponding holes. For lowering onto the water and raising thepontoon 15 to the deck 4 the ship cargo crane 17 is installed on thelatter. The expansion—mooring of the pontoon 15 to the ice-breaker 1 andthe tanker 9 is made with the use of the cables 18. The flexible hose 8is raised from the sea bed through the tubule 7 or the trunk 16 of thepontoon 15 with the use of the capstan 11 and the lifting cable 19 (seeFIG. 6).

For towing, e.g., towing the tanker 9, which is unable to move, theice-breaker 1 is equipped with the towing device 20 (see FIG. 2).

On the deck 4 of the ice-breaker 1 the container 21 is installed (seeFIG. 3) with oil gathering equipment (not shown) arranged in it andintended for liquidating emergency spills of oil.

The ice-breaker 1 is also provided with the necessary fire-fightingmeans (not shown) for liquidating possible fires, e.g., foamextinguishers and carbon dioxide fire extinguishers, mobile andemergency fire pumps, a set of fire-fighting tools and outfit.

On the afterdeck 3 of the ice-breaker 1 the removable platform 22 (seeFIGS. 1, 2, 4, 5, 6, 7) is installed, on which a container (not shown)is arranged for the purpose of gathering possible spills of a liquidmedium, primarily oil, when transporting the latter from the ice-breaker1 into the tanker 9. It helps to avoid pollution of the environment.

On the deck 4 the ecological monitoring laboratory 23 is arranged withthe necessary equipment and instruments. It enables to obtain necessarydata on the effect of the oil shipping and transporting activities onthe environment, develop efficient measures for reducing negativeeffects, timely identify oil leakages, provide information support whenlocalizing oil spills.

The ice-breaker 1 for oil shipping operates in the following way.

The ice-breaker 1 comes to the area where the underwater pipeline withthe flexible hose 8 is located, making the way in the ice for the tanker9. According to this embodiment of using the ice-breaker 1 an offshoreterminal is provided for mooring of the ice-breaker 1. Then the tanker 9is moored to the ice-breaker 1 either directly, or at a distance. Afterfinishing the mooring operations, the ice-breaker 1 is preparing forraising the flexible hose 8 of the underwater pipeline. For this purposea diver is lowered in a cage from the diving station 5 through thediving trunk 6. The diver searches for the flexible hose 8, which is onthe sea bed, attaches the hose 8 to the lifting cable 19 and opens thevalve on the underwater pipeline.

According to the first embodiment of the ice-breaker 1, the tubule 7 isused in the conditions of finely broken ice having the thickness notmore than 1.5 m.

On the afterdeck 3 the tubule 7 is secured. The cable 12 of the capstan11 is attached to the tubule 7, and the latter is lowered along theguides 13 into the trunk 10 so as its lower edge 14 is below the base offloating ice, by 0.5 m or 2 m lower than the CWL of the ice-breaker 1.After finding the hose 8 the dicer attaches the latter to the liftingcable 19. With the use of the capstan 11 the hose 8 is drawn through thetubule 7 onto the afterdeck 3 of the ice-breaker 1 for equipping thehose with the means necessary for oil shipping. During these operationsthe hose 8, owing to the tubule 7, does not contact with ice, whichprevents it from being damaged. The tubule 7 will be in the operationposition until the loading works on the tanker 9 are finished.

According to the second embodiment of the claimed invention the hose 8is lowered and raised and oil is shipped with the use of the pontoon 15lowered from the deck 4 of the ice-breaker 1 through the trunk 16 thatprotects the hose 8 of the underwater pipeline against floating iceduring lowering and raising the hose 8 from the sea bed during oilshipping also. The pontoon 15 may be used in the conditions of finelybroken ice with the thickness not more than 15 cm.

The pontoon 15 is lowered onto the water with the use of the ship cargocrane 17 of the ice-breaker 1. The pontoon 15 is moved, either with theuse of a service boat of the ice-breaker 1 or with the use of themooring mechanisms of the tanker 9 and the ice-breaker 1, to the areawhere the hose 8 of the underwater pipeline comes out of the water. Thehose 8 is passed through the trunk 16 of the pontoon 15 with the help ofa diver, when the capstan 1 1 with the cable 19 is operated, attachingthe latter to the hose 8. Then, the hose 8 is raised onto the afterdeck3 of the ice-breaker 1 for the purpose of equipping it with the meansnecessary for shipping oil (it is provided for when the tanker 9 ispositioned directly to the stem of the ice-breaker 1.

In a case where the tanker 9 is positioned at a distance from theice-breaker 1 (see FIG. 7) by a service boat or with the use of themooring mechanisms of the ice-breaker 1 and the tanker 9, the pontoon 15together with the hose 8 are transported to the tanker 9. The pontoon 15is moored to the tanker 9 or the ice-breaker 1 with the cables 18. Then,the oil sipping operations are performed.

The ice-breaker 1, which is claimed as an invention, enables to carryout works on offshore shipping of oil into the tanker 9 not only in theconditions of initial ice formation, but also in the conditions ofstable fast ice. The ice-breaker 1, independently making a passage inthe ice for itself or, when necessary, going after a linenuclear-powered ice-breaker, e.g., of Taimyr type, comes to the area ofthe underwater pipeline and is fixed with the use of ice anchors. Thetanker 9 comes along the passage to the ice-breaker 1 and is fixed inthe ice passage. Then, the operations on lowering and raising the tubule7 (or the pontoon 15), raising the hose 8 of the underwater pipeline andoil shipping are carried out as described above.

Thus, the use of the ice-breaker 1, which is claimed as an invention,enables not only to ensure offshore shipping of oil from an onshore tankfarm into sea-going tankers in the winter time in the ice conditions,but also, in the result of using the claimed ice-breaker, new functions,not peculiar to an ice-breaker, but necessary for safe shipping of oil,are performed, namely: liquidation of emergency oil spills, liquidationof fires, prevention of the environment in the area of oil shipping frombeing polluted.

The preferred embodiment of the system of single-point mooring andservicing of ships, primarily tankers 9, is shown in FIGS. 8, 9, 10, 11,12.

The system comprises the fixed construction 25 secured to the sea bed 24(see FIGS. 8, 9), which has the rotating device 26 connected with theconstruction with the possibility of turning around the vertical axis,the valve 27 for a liquid medium, primarily oil, the hose-mooring line28 for mooring the tanker 9 and transporting oil from the underwaterpipeline into the tanker 9 through the cargo-receiving device 29, e.g.,a bow receiving device, of the tanker, the weight 30 secured to thehose-mooring line 28, the damping cable 31 connected on one its end tothe rotating device 26 and on the other end to the weight 30. Thehose-mooring line 28 is secured, by its bitter end, to the rotatingdevice 26 of the fixed construction 25. The fast line 32 of thehose-mooring line 28 is provided with the head 33, which is necessaryfor connection to the cargo receiving device 29 of the tanker 9, and theguiding cable 34 connected to the remotely operated buoys 35 taken.e.g., in the quantity of two pieces. The buoys 35 are equipped with theanchoring weight 36 necessary for positioning the fast line 32 of thehose-mooring line 28, when in the non-operative position, on the sea bed24. The buoys 35 are connected to the anchoring weight 36 by the cable37.

The availability of the damping cable 31, which is connected on its oneend to the rotating device 26 and on the other end to the weight 30, inthe system and positioning of the section of the hose-mooring line 28,being between the rotating device 26 and the weight 30, outside the areaof power load action enables to remove the maximum load from the sectionof the hose-mooring line and transfer it via the damping cable 31 andthe rotating device 26 to the fixed construction 25. It helps to avoidpossible breakages of the hose-mooring line 28 during single-pointmooring of the tanker 9.

For the purpose of quickly finding the system of single-point mooringits individual members are equipped with radio receivers and radiotransmitters (not shown). The latter are arranged at the fixedconstruction 25, the weight 30, the head 33 and in the buoys 35. Themoored tanker 9 is equipped with a system (not shown) for automaticallypulling the hose-mooring line 28. The cargo receiving device 29 of thetanker 9 and the head 33 of the hose-mooring line 28 are equipped withmeans (not shown) for automatically disconnecting the hose-mooring line28 from the cargo receiving device 29 of the tanker 9, which arenecessary in a case of emergency.

The system of single-point mooring is provided with the ice-breaker 1(see FIGS. 1, 2) for offshore shipping of oil, which has the divingstation 5, as installed on the deck 3, with the diving trunk 6 forlowering and raising a cage with a diver, who is to open the valve 27for a liquid medium at the fixed construction 25 as well as find andraise the hose-mooring line 28 after its emergency detachment from thecargo receiving device 29 of the tanker 9 in the conditions of close anddrifting ice also.

The method of single-point mooring of the tanker 9 is carried out asfollows.

To the location of the fixed construction 26 with the hose-mooring line28 the ice-breaker 1 comes first, making the way in the ice for thetanker 9. With the use of radio receivers of the ice-breaker 1 or thetanker 9, which are capable of receiving signals from radio transmittersarranged at the fixed construction 25, the weight 30, the head 33 of thehose and the buoys 35, the exact location of the hose-mooring line 28 isdetermined. Apart from this, the ice-breaker 1 continuously clean theplace of mooring of the tanker 9 from ice.

A control signal is sent from the tanker 9 to the remotely operatedbuoys 35, which forces the buoys 35 to automatically disconnectthemselves from the anchoring weight 36, the cable 37 unwinds, thusenabling the buoys 35 to come to the surface. The buoys 35 are caughtfrom the tanker 9 by a known method and raised onboard, then the guidingcable 35 is caught, which is winded on the winch drum and disconnectedfrom the hose-mooring line 28 just after connecting the head 33 to thebow cargo receiving device 29 of the tanker 9.

It should be mentioned at this point that the system enables to moor thetanker 9 at any time, without depending on the dominating wind directionand sea condition, in the direction most convenient for it with thepossibility of turning the tanker 9 roundabout. The possibility oftwisting the hose-mooring line 28 is fully avoided.

A diver in a cage is lowered from the ice-breaker 1 through the divingtrunk 6 from the diving station 5, who opens the valve 27 for a liquidmedium at the fixed construction 25. Then the diver in the cage israised onboard the ice-breaker 1. The latter continues cleaning theplace of mooring and servicing of the tanker 9 from ice.

During the operation of oil shipping into the tanker 9 the tension ofthe hose-mooring line 28 is monitored automatically. As soon as thetension exceeds the allowable norm (in emergencies)., the means forautomatically disconnecting the hose-mooring line 28 from the cargoreceiving device of the tanker 9 act. The hose-mooring line 28 falls onthe sea bed 24. The guiding cable 34 remains winded on the winch drum onthe tanker 9. After liquidating the emergency a diver again is loweredfrom the ice-breaker 1 through the trunk 6, who finds the hose-mooringline 28 and connects the guiding cable 34 with the buoys 35 to it. Theneverything is repeated according to the above described procedure.

Apart from this, in the conditions of close and drifting ice, whichfrequently take place in Arctic seas, when it is impossible to raise thehose-mooring line 28 by the above described method, a diver is loweredthrough the diving trunk 6 of the ice-breaker 1, who connects thelifting cable 19 to the hose-mooring line 28, thus helping to raise thehose-mooring line 28 from the sea bed 24 onboard the ice-breaker 1 andtransfer it to the tanker 9.

It should be mentioned that in liquidating emergencies, in particular afire, a local oil spill, towing of the tanker 9 unable to move, theice-breaker 1 for offshore shipping of oil directly participates, owingto the special equipment available onboard.

Thus, in the result of using this group of inventions, a new technicalresult is achieved—the possibility of offshore shipping of a liquidmedium, primarily oil, from an onshore tank farm into sea-going tankersin the winter time in the ice conditions by ensuring both mooring to anoffshore terminal and single-point mooring of a tanker at any time,without depending on the dominating wind and sea condition, in adirection most convenient for it with the possibility of its roundaboutturning, with the subsequent servicing of it by transporting a liquidmedium into such a tanker.

Consequently, the claimed group of inventions complies with thepatentability criterion of industrial applicability.

By the present time the method of single-point mooring of tankers andthe system for carrying out same with the use of the claimed ice-breakerbased on additionally equipped ice-breaker Captain Nikolaev have passedtests in the Barents Sea in the Timano-Pechora region; the tests haveshown the possibility of the single-point mooring and oil shipping inthe winter time in the ice conditions.

1. An ice-breaker, primarily for carrying out offshore shipping of aliquid medium, preferably oil, comprising a hull with vertical throughguiding trunks and a deck, characterized in that it is equipped with adiving station installed on the deck and communicating with one of thesaid vertical through trunks, the said one trunk being intended forlowering and raising a diver, a device for the protection of a flexiblehose of an underwater pipeline against ice action, the said device beingmade in the form of a cylinder provided with guides for moving inanother vertical trunk made in the stern side of the hull and installedin its travel position on the afterdeck.
 2. The ice-breaker according toclaim 1, characterized in that it is equipped with cargo lowering andlifting mechanisms and a towing device.
 3. The ice-breaker according toclaim 1, characterized in that it is equipped with a container, which isinstalled on the deck and contains oil gathering equipment andfire-fighting means.
 4. The ice-breaker according to claim 1,characterized in that it is equipped with a removable platform, which isinstalled on the afterdeck and has a container for gathering oil spillsand an ecological monitoring laboratory.
 5. An ice-breaker, primarilyfor carrying out offshore shipping of a liquid medium, preferably oil,comprising a hull with a vertical through guiding trunk and a deck,characterized in that it is equipped with a diving station installed onthe deck and communicating with the said vertical through trunk beingintended for lowering and raising a diver, a device for the protectionof a flexible hose of an underwater pipeline against ice action, saiddevice being made in the form of a pontoon having a trunk for servicingof a flexible hose and installed in its travel position on the deck. 6.The ice-breaker according to claim 5, characterized in that it isequipped with cargo lowering and lifting mechanisms and a towing device.7. The ice-breaker according to claim 5, characterized in that it isequipped with a container being installed on the deck and contains oilgathering equipment and fire-fighting means.
 8. The ice-breakeraccording to claim 5, characterized in that it is equipped with aremovable platform, which is installed on the afterdeck and has acontainer for gathering oil spills and an ecological monitoringlaboratory.
 9. A method of single-point mooring and servicing of ships,primarily tankers in the ice conditions, according to which a fixedconstruction secured to the sea bed is used, the said construction beingprovided with a device being connected to it with the possibility ofturning around the vertical axis and a valve for a liquid medium,primarily oil, a mooring line and a flexible pipeline for transporting aliquid medium into a moored tanker through a cargo-receiving device ofthe tanker, characterized in that for mooring a tanker and transportinga liquid medium a mooring line and a hose that are made as a singlehose-mooring line which bitter end is secured on the fixed constructiondevice, are used, an ice-breaker ensuring offshore shipping of oil isadditionally used, the said ice breaker being equipped with a divingstation installed on the deck and communicating with a trunk forlowering and raising a diver, who opens the valve for a liquid medium,finds the hose-mooring line and raises it to the tanker after emergencydetachment of it from the cargo-receiving device of the tanker in theconditions of close and drifting ice.
 10. The method according to claim9, characterized in that a weight is attached to and a damper beingmade, preferably, in the form of a cable and connected on one its endwith the device of the fixed construction and on the other end with thesaid weight, is installed on a section of the hose-mooring line near itsbitter end.
 11. The method according to claim 9 or claim 10,characterized in that a section of the hose-mooring line, which islocated between the device of the fixed construction and the weight, isinstalled outside the area of action of power loads.
 12. A system ofsingle-point mooring of ships, primarily tankers in the ice conditions,comprising a fixed construction secured to the sea bed and having adevice being connected to it with the possibility of turning around thevertical axis and a valve for a liquid medium, primarily oil, a mooringline and a flexible pipeline for transporting a liquid medium into amoored tanker through a cargo-receiving device of the tanker,characterized in that the mooring line and the hose for transporting aliquid medium are made as a single hose-mooring line which bitter end issecured on the fixed construction device; the system is provided with anice-breaker ensuring offshore shipping of oil, which has a divingstation installed on the deck and communicating with a trunk, arrangedin the hull, for lowering and raising a diver, who opens the valve for aliquid medium, finds and raises the hose-mooring line after emergencydetachment of it from the cargo-receiving device of the tanker in theconditions of close and drifting ice.
 13. The system according to claim12, characterized in that it is provided with a weight is attached tothe hose-mooring line near its bitter end and a damper being made,preferably, in the form of a cable and connected on one its end to thedevice of the fixed construction and on the other end to the saidweight.
 14. The system according to claim 12 or claim 13, characterizedin that a section of the hose-mooring line, which is located between thedevice of the fixed construction and the weight, is outside the area ofaction of power loads.